[Markdaspark]

Hi,
This is my first post to this forum, (or any forum for that matter) so I hope I in the right place.
I live in Banstead, Surrey. A friend of mine lost all his Koi last week. Got up in the morning to find them floating. Most of them he has had for over 20 years so were about 24" long. He has done nothing different to his pond to what he has been doing in the past. 4 days previous he did a 30% water change but has done this many times. The only thing he did say is the bottom of the pond was covered in fish eggs. So much so he had trouble walking about to get to the Koi. The gold fish in the same pond are fine as is 1 small Koi.
I asked if he did a scrape or tested the water, he has never done ether and was too depressed to talk about it any more.
Any idears

[miles41]

Blimey, what a sad post I would be testing the water straight away, as to loose all the fish in one go; something serious has happened. A scrape of the dead fish would have been good, but maybe too late now?
I know it's a horrible thought, but the pond hadn't been 'targeted' by someone had it?
Good luck to your mate in the search on this.

[bcfc]

has said, sad post to loose all ur koi. test water first? kh? mybe a ph crash? air in pond? it has been hot? scrape?

[Doghouse Riley]

Strange if there were no symptoms shown the previous day, my first thought too was vandalism.

However, this reminds me of decades ago when all the fish in the pond in St James Park died overnight one summer.
It was determined that in the very hot weather there was a lack of oxygen in the water due to the prevaling atmospheric conditions.

[Boo!]

agree with those above:

Increased temps remove oxygen from the pond - how much o2 did he have going in?

A release of eggs and not cleaning afterwards - would i imagine send water parameters through the roof! Ammonia spike / filters trying to cope leading to nitrite spike / still no removal of contaminants into the pond - was a ticking timebomb i think? Thing is - he sounds like an established koi keeper who has been through many springs and summers with his fish, how odd that he hasnt changed his maintenance routine following something like a spawn and yet this time everythings gone horribly wrong for the poor man! Also odd i guess that all fish went at once - but perhaps massive ammonia spike coupled with a really hot day and lack of o2,,,,

Still i am sure there will be others along to offer their opinion shortly. My condolences to your friend - he must be gutted

Lx

[Davej]

Any attempt at diagnosis would be a guess - but a very sad story, feel for your friend.

Dave

[JoeB]

My father lost all his koi a few years ago - He got the Envirment Agency in to check the water and it was put down to a local farmer sprayimg his crops

[Bryan from Wymondham]

Shocking to read that, I know how he must feel. I lost a load of fish a few years ago one summers night when the pumps failed.

[Limey]

That is VERY sad . Lack of oxygen is a possible - 1 small koi survivng plus goldfish maybe points to that as a possible. A scrape well don't think any parasite could kill overnight . The other things said was a 30% water change... so doubt a ph crash BUT could there have been something going on and water company had upped some 'ingredient' - don't they do that iof they have some probs with weater and just maybe the change was done at the wrong time.

Bottom line prob never know for sure, just really feel for your friend, must be devesatated after having some of those fish so long

[Essex]

Sad to hear.

Boo covered most areas very well.



But as Davej said ' There are too many variables to actually start guessing.

Definitively a hands on needed from experienced people who think like above.

Keep us informed if you can, it helps us to be reminded in not being complacent.